Blood lancet devices are primarily used by diabetes patients who are required to regularly check their blood sugar levels, but they are also used in numerous other areas where the collection of blood is required. A blood lancet device is composed of a body and a lancet that is made of a needle fixed to the body. By giving elasticity to the lancet, the needle goes into the skin to a particular depth to collect blood. The U.S. Pat. No. 4,517,978 conforms to this description. In this patent, when a trigger is pressed after the lancet is inserted and the sleeve is pulled back, the lancet is fired forward. At this time, a needle briefly penetrates the skin and is then withdrawn.
In this type of blood lancet device, which was the type generally sold in the market, the depth of penetration achieved by the needle was uniformly fixed. However, people's skin can have different thicknesses, and blood needs to be collected from different parts of the body, so it was frequently necessary to adjust the depth of the needle's penetration of the skin. To achieve this, a device that could adjust the depth of penetration was developed. The U.S. Pat. No. 5,613,978 shows the structure of this device in detail. With the patented device, a user can adjust the depth of the needle's penetration of the skin by turning a control tip.
On the other hand, as a lancet penetrates the skin, in order to prevent infection it should be used only once. Therefore, the user should remove the lancet from the blood lancet device and dispose of it after use. Currently, users of the device, such as doctors or nurses, tend to pay less attention to the need to change the lancet as time goes on, so cases of infection often occur that are caused by the lancet needle.
As the lancet needle penetrates the skin, use of the lancet is accompanied by pain. People regard this pain as a natural aspect of blood collection.